The purposes of this investigation are: 1) to determine the efficacy of promoting patient self care during cancer treatment for women having a diagnosis of breast cancer through nurse interventions that provide information, enhance patients' ability to use the information and/or support uncertainty-reducing interpretations of illness related events; 2) to describe concomitant factors and the influence of time as variables that enhance or that limit self care activities during and following breast cancer treatment; and 3) to describe the efficiency of a model of nursing care for women with breast cancer within a health maintenance organization (HMO) and within a large private practice site. The study contains three components: 1) a multivariate experimental analysis of nurse intervention assessment base, operation, effect and durability relative to four outcomes; self, care, self help, life quality and morbidity. This analysis allows determination of which nursing interventions are effective in promoting patient self care among women receiving treatment for breast cancer; 2) analysis of covariance of concomitant variables and multiple regression/correlation analysis (MRC) of the effect of time on the learned process of self help during cancer treatment experience. Analyses include testing the effect of groups of concomitant variables: Person Conditions, e.g., ethnic origin, information seeking style, etc.; Disease Conditions, e.g., type of tumor, type of treatment, etc; Contextual Conditions, e.g., place receiving treatment, social support, etc. These analyses provide description of conditions which influence the utilization of self care during treatment for breast cancer; and 3) a cost effectiveness analysis of program of nursing care offered to selected cancer patients within an HMO and within a private physician care setting. The design for the multivariate experimental analysis is a 3X2X2 randomized block, repeated measures design with three levels in the learning context treatment factor crossed with two levels in the reinforcement factor. Two levels of enabling skill represent the blocked factor. The three levels of the learning context are: Self help class, independent study, natural condition. The two levels of the reinforcement are: Nurse case manager and natural condition. Interventions selected are based on health education research findings that sharing of information alone is insufficient for behavior change and previous experience with self care promoting self help classes.